Apparatus for pressing detergent cakes



Nov. 14, 1961 w. BOYD APPARATUS FOR PRESSING DETERGENT CAKES Filed Aug. 6, 1959 INVENTOR. VV/LL/AM BOYD A TTORNEY United States Patent 3,008,211 APPARATUS FOR PRESSING DETERGENT CAKES William Boyd, Toronto, Ontario, Canada, assignor to Colgate-Palmolive Company, New York, N.Y., a corporafion of Delaware Filed Aug. 6, 1959, Ser. No. 832,111 3 Claims. (Cl. 257) The present invention relates to a new apparatus for pressing detergent materials into cake form. More particularly, the invention is of an apparatus for manufacturing detergent cakes at high speed, which, in such manufacturing operation, prevents harm to pressing dies employed, which otherwise would be damaged in pressing of the occasional production of double cakes or oversized detergent cakes.

In accordance with the invention there is provided an apparatus for pressing detergent materials into cake form at high speed, e.g., about 30 to 200 cakes per minute, which comprises a moving die box, having a cavity therein which passes through a plurality of positions, including a charging position, pressing position, an ejection position and a dead or clearing position, a pair of relatively movable opposed reciprocating campanion die members which, upon application of a pressing force, enter the die box cavity at the pressing position and press a detergent blank in that cavity into cake form; means for discharging pressed cakes of detergent at the ejection position, means for clearing any remaining detergent materials from the die box cavity at the dead position, means for feeding detergent blanks into the die box cavity for pressing and means for exerting a pressing force on the dies when the die box cavity containing a detergent blank is at the pressing position. The detergent cake made by the apparatus of this invention may be made of soaps, synthetic organic detergents of the anionic or nonionic types, or mixtures of soaps and/or detergents, provided that these compositions are sufliciently plastic and form-retaining to be pressed into stable shapes.

In operation of a preferred detergent press of the type described a blank of detergent is placed in one cavity of a multi-cavity rapidly intermittently rotating die box at a charging station, the die box is rotated ninety degrees to a pressing station where the blank is compressed in the die box cavity by reciprocating dies and is then ejected after an additional ninety degrees rotation. For any of various reasons, occasionally the pressed detergent cake is not completely discharged as it should be. Upon further rotation to a charging station of the cavity containing the retained detergent, a new blank is thrust into the die box. When such an overcharge of detergent in the die box is pressed, the product resulting is oversized and is apt to come apart readily in use, along the boundary of the tWo pieces of detergent charged. To avoid this condition and the difficulties encountered and damage done to equipment because of the presence of such oversized cakes, the present invention provides for a thorough clearing of the die box cavity after the discharge station of the rotating die box and before the station in which a new blank is added.

The structure, function and advantages of this invention will be apparent from reference to the following detailed description of a preferred form thereof taken in conjunction with the accompanying drawings in which:

FIG. 1 is a perspective view, with some parts removed for clarity of exposition, of a high speed detergent pressing apparatus embodying a form of the invention;

FIG. 2 is a side elevation of a combination of ejecto-rs for discharging the pressed soap cake and for clearing a die box cavity from which the pressed cake was supposed to have been ejected; and

FIG. 3 is a plan view of the combination of ejectors shown in FIG. 2.

3,008,211 Patented Nov. 14, 1961 A rotating cruciform die box spider 11 contains a plurality of die boxes 13 defining cavities 15. This spider is at the heart of a detergent pressing machine 17. In the simplified embodiment of the machine illustrated there are shown four such cavities. However, it should be understood that the invention is also equally applicable to modifications of this machine which press a plurality of cakes at once and sometimes also impart a plurality of forming and pressing strokes to each cake. In the illustration the lowermost die box of the spider is at the charging station. That to the right is in the pressing station and the cavity at the top is at the discharging station. The die box at the left of the illustration is in what may be charactreized as a dead station, i.e., a place where there is normally no charging, pressing or discharging activity.

The rapid, repeated operations of the present machine may be considered as beginning when pre-cut blanks of detergent 19 are fed by moving belt 21 to an elevating mechanism 23 which raises them to a position even with the die box cavity at the charging station, where plunger 25, indexed to the rotation of the die box spider and powered by suitable means, forces the detergent blank into the die box charging cavity. After a rotation of the spider ninety degrees counterclockwise, dies 27, fastened by backing plates '29 to rams or pressing means 31, are brought together by the forces exerted by those pressing means to shape the detergent blank into desired cake form inside the die box cavity. While one blank is being pressed, another is added to the cavity then at the charging station. After pressing, the reciprocating dies are Withdrawn, leaving detergent cake inside the die box, which is then further rotated ninety degrees to discharge position. There is a pair of dies for each die box cavity at the pressing station, of which there is only a small whole number, e.g., 1, 2, 3. At the discharge station is positioned an ejector 33 connected to any suitable source of reciprocating motion indexed with the movement of the spider. To simplify the drawing, the source of reciprocating motion has not been illustrated. When the die box containing pressed detergent cake is in the discharge position, ejector 33 is driven into the discharge cavity and displaces the pressed cake, which then falls onto take-off belt 35, which delivers it to an automatic wrapping machine.

Simultaneously with the movement of ejector 33, another ejector or pusher 37 passes through another cavity of the die box in a dead station ninety degees further advanced than the discharging station. Both ejectors are joined to an angular connective force transmitting member 39, which in turn transmits the ejecting force and motion to them from an appropriate indexed source, not shown, and both move substantially at right angles to the plane of the die box. Another ninety degree movement of the spider brings the cavity just discharged to safety clearing position. After safety clearance of the cavity by ejector 37 the empty cavity is moved a further ninety degrees to loading position. At the point at which detergent cakes or fragments are cleared it is beneficial to install a chute and sufliciently large collecting container, taking care to so design these as to avoid blocking of the ejecting mechanism. The presence of the chute and collector allows easy determination of the efliciency of the discharge ejector, prevents accidental blocking of clearing by any nearby machine parts and avoids untidy and dangerous deposition of detergent cakes on the floor of the Working space.

ally has attached to the face thereof a resilient material 34, such as sponge rubber or foam plastic of suitable properties, so that the ejected soap cakes will not bear markings impressed on them in the ejection process. In the embodiment illustrated, the cjectors are welded to the integrating or connective member 39 at 41 and 43 but other methods of afiixation are also suitable.

In operation the present invention assures that the die box cavity is perfectly clear of all detergent material when it is brought into charging position. This prevents filling of the die box with more soap or detergent than the precise desired volume of the measured detergent blanks. Under ideal conditions ejector 33 clears the die box of pressed cake so that there is no unwanted soap in the cavity, either at the dead station or before charging. However, due to any of awide variety of causes, occasionally the die box will not be satisfactorily cleared by the discharge ejector or, if the cake is satisfactorily discharged, sometimes the same or different pressed cake might be forced back into the die box after discharge, These adverse conditions may be brought about by breakage of the ejector, slipping of a set screw used to fasten the ejector in place, excessive wear of the cushioned ejector face, blocking of the discharge belt by a build-up of pressed cakes near the discharging point, and so forth. When pressing detergents containing synthetic organic non-soap detergent substances, blocking of the discharge belt is sometimes caused by the pressed cake prematurely and irregularly falling out of the die box, a phenomenon not usually noted with soap alone. This condition is accentuated by an asymmetric cake shape. It can be minimized by perimetrically grooving the die box interior wall, which serves to retain the cake in place until discharged by ejector 33. If the die cavity was not continually and positively cleared of any unwanted soap pieces, the presence of such pieces in the box, together with the fresh blank of soap or synthetic detergent charged to that cavity, would result in the production of an oversized cake. Such a cake would be of greater thickness than desired and might jam the automatic feeding and Wrapping machinery employed in conjunction with the detergent press.

When metal dies and die boxes are employed, the pressing of an oversized cake of detergent would not usually adversely atfect the condition of the dies, although some detergent might be extruded out of the die box and onto the automatic pressing machinery, from which it could subsequently be accidentally returned to the pressing cavity together with possible accumulation of dirt, grease or rust to cause defacing of subsequently pressed cakes. While rigid dies and die boxes are not disfigured or de-. stroyed by pressing excessive quantities of detergent at a time softer dies will often be rendered inoperative by a single attempt to press an oversized blank or combination of a blank and part of a previously pressed cake.

Softer dies for pressing detergent cakes are made with certain parts of the dies of a polymeric synthetic organic plastic, e.g., as polyethylene, polypropylene, nylon. Such dies are of a construction which provides a sufficient working clearance between dies and die box as the dies enter but allows expansion of the dies, especially the leading edges thereof, to the die box walls during pressing, the expansion being due to the pressure exerted on the dies by the detergent blank as it resists compression. Usually substantially the whole die is made of a plastic sufliciently firm to press out the detergent cake and still resilient or flexible enough to expand to the die box wall during pressing, but sometimes only certain parts or leading edge portions are made of such substance, the rest of the die being of rigid material such as steel, brass or a different suitable plastic.

Failure of softer die members such as those described above, is caused by the spreading action of the detergent material on the die as the detergent is compressed. Because the dies contact the detergent earlier than would be the case with only a correctly cut blank inside the die box,

the flexible or resilient edges of the dies spread outwardly prematurely, often before even entering the die box, and these die edges are ripped or severely abraded by such contact. In light of the above discussion, it is evident that even a very rare double-caking in an automatic pressing operation will destroy resilient pressing dies and will necessitate machine shut-down for replacement. Such shutdowns are costly in loss of production.

The drawing and description of the invention illustrate a preferred embodiment in which, subsequent to the pressing and discharging stations, an ejector clears the die box cavity in a dead station. As shown, this ejector is affixed to and co-acts with the discharge ejector. It will be evident to those of skill in the art, having this specification before them, that various equivalents may be substituted for the ejector mechanism and other elements shown. Thus, a mechanical ejector, non-integral with the discharge pusher and independently indexed to the rotation of the spider might be substituted. Pneumatic means, such as compressed air may be used to empty the die box. The ejection means for clearing the die box after the normal discharge operation may be one which operates at any point between normal discharge and charge positions, although it is preferred to carry out this operation at a dead station intermediate the discharge and recharging positions.

This invention is not limited only to the embodiments shown because it is obvious that modifications of the invention may be made and equivalents may be substituted therein without departing from its spirit or transcending the scope of the claims.

What is claimed is:

1. An apparatus for pressing detergent materials into cake form at high speed which comprises a rotating die box having a plurality of forming cavities therein, which rotates intermittently through a plurality of stations, including a charging station, a pressing station, an ejection station and a clearing station, means for feeding a detergent blank to be pressed into the die box cavity at the charging station, a pair of relatively movable opposed reciprocating companion die members of cross-sectional area less than the cross-section of the die box cavity, so as to provide a working clearance between dies and die box, the die members having pressing surface leading edge portions of polymeric shynithetic organic plastic, sufiiciently firm to press detergent cakes into desired shape and flexible and resilient enough to expand to the die box wall during the pressing operations, due to the pressure exerted thereon by the detergent blank as it resists compression, which d-ie members enter the die box cavity at the pressing station and press a detergent blank in that cavity at the pressing station into cake form, means for exerting a pressing force on the dies when the die box cavity containing a detergent blank is at pressing position, means for discharging a pressed cake of detergent at the ejection station and pusher means for clearing any remaining detergent material from the die 'box cavity in the clearing station at the same time the ejecting means is discharging a pressed cake at the ejection station, the pusher clearing means having a contacting surface approximating the cross-section of the die box cavity and moving into the die box cavity substantially at a right angle to the plane of rotation thereof.

2. An apparatus for pressing detergent materials into cake form at high speed which comprises a rotating die box having a plurality of forming cavities therein, the number of cavities divided by four being a small whole number, which die box rotates intermittently through four stations, situated approximately ninety degrees apart, including charging, pressing, ejection and clearing stations, means for feeding detergent blanks into the die box at the charging station, a small whole number, equal to the number of forming cavities divided by four, of pairs of relatively movable opposed reciprocating companion die members of cross-sectional area less than the cross-Section of the die box cavity so as to provide working clearance between dies and die boxes, the die members having pressing surfaces of polymeric synthetic organic plastic, sufliciently firm to press detergent cakes into desired shape and flexible and resilient enough to expand to the die box wall during the pressing operation, due to the pressure exerted thereon by the detergent blank as it resists compression when the die members enter the die box cavity at the pressing station and press a detergent blank in that cavity into cake form, means for exerting pressing force on the dies when the die box cavity, containing detergent, is at pressing position, means for discharging pressed cakes of detergent onto a take-off belt at the ejection station and pusher means for clearing any remaining detergent material from the die box at the clearing station at the same time the ejecting means is discharging pressed detergent at the ejection station, the pusher clearing means having a contacting surface, approximating the cross-section of a die box cavity and moving into such cavity in a path substantially perpendicular to the plane of rotation of the die box.

3. An apparatus for pressing detergent materials into cake form at high speed which comprises a rotating die box having a plurality of forming cavities therein, the number of cavities divided by four being a small whole number, which die box rotates intermittently through four stations, situated approximately ninety degrees apart, including charging, pressing, ejection and clearing stations, means for feeding detergent blanks into the die box at the charging station, a small Whole number equal to the number of forming cavities divided by four, of pairs of relatively movable opposed reciprocating companion die members of cross-sectional area less than the cross-section of the die box cavity so as to provide working clearance between dies and die box, the die members having pressing surfaces of polymeric synthetic organic plastic, sufficient-1y firm to press detergent cakes into desired shape and flexible and resilient enough to expand to a die box wall during the pressing operation, due to the pressure exerted thereon by the detergent blank as it resists compression when the die members enter the die box cavity at the pressing station and press a detergent blank in that cavity into cake form, means for exerting pressing force on the dies when the die box cavity, containing detergent, is at pressing position, pusher ejection means for discharging pressed detergent cakes onto a take-0E belt at the ejection station and, fastened to the ejection means, pusher means for clearing any remaining detergent material from the die box cavity at the clearing station when the ejection means is discharging pressed detergent at the ejection station, the clearing means having a contacting surface approximating the cross-section of the die box cavity and, together with the discharging means, moving into the die box cavity substantially at right angles to the plane of rotation of the die box.

References Cited in the file of this patent UNITED STATES PATENTS 784,470 Church Mar. 7, 1905 1,692,322 Aiken Nov. 20, 1928 1,956,532 Jones Apr. 24, 1934 FOREIGN PATENTS 519,980 Belgium May 30, 1953 577,686 Canada June 16, 1959 

1. AN APPARATUS FOR PRESSING DETERGENT MATERIALS INTO CAKE FORM AT HIGH SPEED WHICH COMPRISES A ROTATING DIE BOX HAVING A PLURALITY OF FORMING CAVITIES THEREIN, WHICH ROTATES INTERMITTENTLY THROUGH A PLURALITY OF STATIONS, INCLUDING A CHARGING STATION, A PRESSING STATION, AN EJECTION STATION AND A CLEARING STATION, MEANS FOR FEEDING A DETERGENT BLANK TO BE PRESSED INTO THE DIE BOX CAVITY AT THE CHARGING STATION, A PAIR OF RELATIVELY MOVABLE OPPOSED RECIPROCATING COMPANION DIE MEMBERS OF CROSS-SECTIONAL AREA LESS THAN THE CROSS-SECTION OF THE DIE BOX CAVITY, SO AS TO PROVIDE A WORKING CLEARANCE BETWEEN DIES AND DIE BOX, THE DIE MEMBERS HAVING PRESSING SURFACE LEADING EDGE PORTIONS OF POLYMERIC SHYNTHETIC ORGANIC PLASTIC, SUFFICIENTLY FIRM TO PRESS DETERGENT CAKES INTO DESIRED SHAPE AND FLEXIBLE AND RESILIENT ENOUGH TO EXPAND TO THE DIE BOX WALL DURING THE PRESSING OPERATIONS, DUE TO THE PRESSURE EXERTED THEREON BY THE DETERGENT BLANK AS IT RESISTS COMPRESSION, WHICH DIE MEMBERS ENTER THE DIE BOX CAVITY AT THE PRESSING STATION AND PRESS A DETERGENT BLANK IN THAT CAVITY AT THE PRESSING STATION INTO CAKE FORM, MEANS FOR EXERTING A PRESSING FORCE ON THE DIES WHEN THE DIE BOX CAVITY CONTAINING A DETERGENT BLANK IS AT PRESSING 